1. Field of the Invention
The present invention relates to a mold and a method for producing two-color injection-molded parts. More particularly, the present invention relates to a mold and a method for producing two-color injection-molded parts, in which a pressure difference between two kinds of molding materials, which are simultaneously injected, is induced so that one of the molding materials is infiltrated into and bonded to the other molding material during solidification.
2. Description of Related Art
It is well known that an injection molding process is used to manufacture plastic parts in the field of automotive industry. In general, the injection molding process uses plastic materials that have a single color to manufacture plastic parts having the corresponding color.
A component of a vehicle such as a door panel, for example, is generally formed of a plastic material having a single color, which does not make a good impression on users. As an alternative plan, a door panel assembly is manufactured by assembling a plurality of parts having at least one color.
However, such a method has problems in that the process of assembling the plurality of parts which constitute the door panel assembly is time consuming, and thus increases the manufacturing cost. In order to solve such problems, conventionally, molding materials having different colors are used to produce two-color injection-molded parts.
FIG. 1 is a diagram schematically showing a conventional process for producing two-color injection-molded parts.
As shown in FIG. 1, the conventional method for producing two-color injection-molded parts uses a mold including two cavities in which molding materials having different colors are filled. After a first molding material is firstly injected into a first cavity 1, a second mold block 4 is moved back to open a second cavity 2, and then a second molding material is secondly injected into the second cavity 2. A holding pressure is maintained until the injected molding materials are solidified and a cooling step is performed such that the firstly injected molding material and the secondly injected molding material are bonded to each other, thus obtaining the two-color injection-molded part.
However, the above-described conventional method for producing two-color injection-molded parts has problems in that, since the cycle time is increased since the process of moving back the second mold block 4 and the first and second injection processes are performed step by step with a time difference, the manufacturing time and cost are increased.
Moreover, since the second injection process is performed after the firstly injected molding material is solidified, the adhesion strength between the first and second molding materials is reduced.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.